Posts filed under Operating Systems

Changing SSL Certificates in a ISPConfig v3 Configuration

When you install a Perfect Server based on Centos and ISPConfig v3.x, the system / 'installer' creates for the components self-signed certificates. All these certificates will generate different warnings in your browser, mail clients etc. So time to eliminate those warnings.

First I needed to find out where all those certificates are located, and what there formats are. In my case, there are three services that use SSL/TLS in some form;

  1. Postfix SMTP service
  2. Courier IMAP service
  3. http / Apache2 webservice

Checking the configuration files will reveal their locations.

Posted on January 7, 2012 and filed under Linux, Operating Systems, Security, Software, Tips'n Tricks.

Screen Capture Can't Be Saved

After upgrading my iMac to OS X Lion (10.7) everything works (or at least seems to work), until I tried to do a screen capture with the built-in tools.

Things that worked:

  • Capturing the entire desktop to file
  • Capturing a selection (using the cross-hair) to file
  • Capturing the entire desktop to the clipboard
  • Capturing a selection (using the cross-hair) to the clipboard

Things that didn't work:

  • Capturing entire windows to file or the clipboard (SHIFT-COMMAND-4 + SPACE / SHIFT-COMMAND-3 + SPACE)

All I got was a weird notification box with the message:

Screen capture can't be saved

The console application also showed an error message:

12/16/11 1:40:08.762  com.apple.SystemUIServer.agent: screencapture could not capture window 3c

Lurking around the Interwebs, I found this seem to occur after an upgrade of the OS, but real solutions are hard to come by.

This is what I did to solve my problem:

  • Remove the screencapture PLIST (preferences) file (~/Library/Preferences/com.apple.screencapture.plist)
  • Copy a com.apple.screencapture.plist file from a working OS X Lion environment and place it in the correct location on the troubled OS X installation.

That seemed to result in two com.apple.screencapture.plist files (one with an additional extension of .locked). I removed the .locked file, rebooted the iMac, and screen capture worked again.

I must mention that I didn't see the .locked file initially. Could be that it existed before. In which case I probably did more than was required to get things fixed....

Posted on December 16, 2011 and filed under Annoying, Apple, Operating Systems, Tips'n Tricks.

Unofficial iOS5 upgrade

After reading the iOS5 upgrade on the Lifehacker website, I decided to upgrade my iPad2 to iOS5. It's unofficial, because iOS5 hasn't been released yet. The version mentioned on the Lifehacker websites is considered to be the Gold-Master version. Meaning that it's the final version, waiting to be released somewhere this month.

First I installed the iTunes beta version as mentioned and downloaded the appropriate iOS versions for my iPad and iPhone. The upgrade went extremely well. Just remember to backup your device before the 'upgrade' proceding.
After the iPad upgrade, I decided to upgrade my iPhone3gs. This went as smooth as the iPad upgrade.

The biggest new feature for me so far is the possibility to use custom text/notification tones. The iPhone3gs also feels more responsive.

There was one annoyance with the initial configuration of the iPad;
My Apple ID was a basic username, and not an e-mail address. This is NOT accepted by the initial iOS5 configuration wizard. Your Apple account NEEDS TO BE an e-mail address. It took me a while to set that up properly in my online account settings.

Posted on October 9, 2011 and filed under Apple, Operating Systems, Software, Tips'n Tricks, iPhone.

Burn OS X Lion Installation Package to DVD

The moment you download OS X Lion, you'd better have a copy of OS X Snow Leopard, because by default the new Apple OS can only be installed on a previous installed Operating System (upgrade). So if you need to reinstall your Mac in the future, you need to install OS X Snow Leopard first, and then upgrade to OS X Lion. Also, there's no way of ordering an OS X Lion copy on DVD..... Well, that sucks.

Fortunately, there's a way of creating the installation DVD by extracting the actual disk image from the downloaded OS X Lion installation package.

Posted on July 20, 2011 and filed under Apple, Operating Systems, Software, Tips'n Tricks.

Weird 802.1x EAP-TLS Behavior with Windows XP SP3

I'm currently busy with several 802.1x implementations in corporate networks, and in one of those environment I get the strangest behavior in regards to the authentication process.

In this particular case I use a Microsoft 2008 Active Directory. Mandatory for distributing the wired network adapter settings in regards to 802.1x. The clients are a mix of Windows XP (SP1 and SP3) clients and some newer and/or exotic operating systems. The authentication mechanism of choice is EAP-TLS with dynamic VLAN assignment. The RADIUS server used is the Cisco Secure ACS v5.x appliance.

During the authentication process of the XP SP3 PC's I saw that the first authentication attempt was made with the PEAP mechanism. Since PEAP isn't allowed, the authentication mechanism failed. About a minute and twenty seconds later the PC started another dot1x authentication sequence. This time using EAP-TLS, and the PC got access to the network.

Posted on January 29, 2011 and filed under Annoying, Operating Systems, Security.

OS X Kerberos / Open Directory Logging

Ever since I switched to OS X server at home I use Splunk> to see what's happening 'underneath the hood'. This revealed that there's a lot (really a whole lot) of Kerberos logging going on. Each and every day I get thousands of log entries regarding krb5kdc which results in over 1 million log entries only for krb5kdc in little over a week.

These syslog messages only contain the following 'text';

krb5kdc[16179](debug): routing msg not interesting
krb5kdc[16179](info): got routing msg type 5(RTM_LOSING) v5
krb5kdc[16179](info): routing socket readable

Looks like that the debugging level is set to debug (why??). And why can't we change it? Others seem to have this problem as well.

Looks like that the following command seems to work:

sudo defaults write /Library/Preferences/DirectoryService/DirectoryServiceDebug "Debug Logging Priority Level" FALSE

After entering that 1 line I haven't seen any new logentries in the kdc logs. More info on that command can be found @ Apple.

Nevermind......

Posted on July 22, 2010 and filed under Annoying, Apple, Operating Systems.

The Problems with Apple OS X (10.6.4) Server

It has finally been done. I've switched off the old Windows 2003 server at home and officially replaced it with an Apple Mac mini server. For now... And with 'for now' I really mean for now. It turns out that Apple OS X Server doesn't resemble its client counterpart at all. Where the client is stable and intuitive, the server edition lacks both.

I'll try to explain why I think there's lots of room for improvement. Mainly stuff I ran into while configuring the server/services.
Since the Windows fulfilled several functions, I needed these functions to be available on the OS X server as well. These were;

  • Networking services like DNS and DHCP
  • Webserver
  • Mailserver
  • MySQL Database
  • SSH Server
  • File sharing on the internal network
  • Public Key Infrastructure for issuing certificates
  • Download station

Evaluating these functions, one would think that this shouldn't be a problem. Well it actually is.... At least some of those features.

Posted on July 12, 2010 and filed under Annoying, Apple, Operating Systems, Switched2Mac.

Installing & Configuring CentOS 5.4 (Day 2)

Oké. Day 2. After the successful installation and configuration of CentOS with Adobe Coldfusion, I needed to install MySQL as a database. So, I started the virtual machine, and found out why Linux will (probably) never cut it as a common desktop environment.

X11 - No DesktopYesterday I (properly) shutdown the system (which had the GNOME Desktop), and today it started with some back to the 60's desktop. Every icon gone. All that I'm left with was a terminal window, clock, and a FireFox window. This environment is the basic X11 desktop.

Posted on April 2, 2010 and filed under Annoying, Linux, Operating Systems, Personal, Tips'n Tricks.

Apple Released OS X Update 10.6.3

Apple released the .3 update to Snow Leopard (10.6) today. You can find this update under the Software Update menu, or on the Apple website as a single (combo) download [.dmg].

The update was ~450MB, and took about ten minutes to install. After the reboot everything seemed to work fine. Some applications (I guess the ones that got updated) reverted back to their default settings. E.g. Firefox wasn't my default browser anymore, but NetNewsWire was still my default RSS reader.

I also thought that QuickTime X (how I dislike that app....) reverted back to its default settings, since my pr0n..... euh movies started opening in different windows. Since I can't find a Terminal command for this on the Internet, I guess that I'm mistaken on that. I might be confusing the excellent QuickTime Pro v7.x with this piece of whatever.
There are no visible enhancements on QuickTime X

An annoyance that got fixed is the deletion on SMB shares (Windows 2003 Server). Without the update, the files got deleted, but the directory they were in stayed behind. When you tried to remove this directory, you got this fancy error code.

The important pieces of software that functioned properly after the update uncluded:

  • Adobe Photoshop CS4
  • Adobe Lightroom v2.6
  • BBEdit v9.2.1

Anyway, (more) updates will follow when I run into unexpected behavior.

Posted on March 29, 2010 and filed under Apple, Operating Systems, Software.

Microsoft Haunted by 17-year old 'feature'

It looks like that every Windows version is susceptible to a 17-year old 'feature' that could give hackers access to your computer. The 'feature' exist since Windows v3.51, which dates from the last century (this way it looks even older :-) )

The person (Tavis Ormandy) who discovered this feature did a full disclosere which can be found here. So you'd better start watching your 3.51 Operating Systems (and above).

Posted on January 22, 2010 and filed under Microsoft, Operating Systems, Security.